Enhanced Endurance in Trained Cyclists During Moderate Intensity Exercise Following 2 Weeks Adaptation to a High Fat Diet

Summary:

The following information was written by Atkins professionals.

This study sought to compare the effects of two weeks of a high-fat, low-carbohydrate diet (70% fat, 23% protein and 7% carbohydrate) with two weeks of a high-carbohydrate, low-fat diet (74% carbohydrate, 14% protein and 12% fat) on exercise performance. Five trained cyclists were required to perform a host of cycle tests at various intensities and lengths of time. Based on the results of these tests, exercise time to exhaustion during high intensity exercise was not significantly different between groups. However, when comparing the different diet groups’ performance during moderate intensity exercise, time to exhaustion was significantly longer after subjects followed the high-fat diet, despite starting off with lower muscle glycogen content (stored glucose). Subjects in the high-fat group also had a lower respiratory quotient, indicating that they were burning fat for fuel in place of carbohydrate.

Commentary:

The following information was written by Atkins professionals.

These findings can be applied to the Atkins Principle of Good Health. Controlled carbohydrate nutrition may improve athletic performance. Although not affecting anaerobic (high intensity) performance, a low-carbohydrate/high-fat diet significantly improved aerobic (moderate intensity) performance in trained cyclists. These individuals were able to pedal nearly 40 minutes longer than individuals eating a standard high-carbohydrate diet.